U.S. patent application number 15/762817 was filed with the patent office on 2018-09-27 for process for producing aromatics from a heavy hydrocarbon feed.
The applicant listed for this patent is SABIC Global Technologies B.V.. Invention is credited to Luis Aramburo, Dustin Farmer, Scott A. Stevenson, Emiel van Kimmenade.
Application Number | 20180273857 15/762817 |
Document ID | / |
Family ID | 54252091 |
Filed Date | 2018-09-27 |
United States Patent
Application |
20180273857 |
Kind Code |
A1 |
Aramburo; Luis ; et
al. |
September 27, 2018 |
PROCESS FOR PRODUCING AROMATICS FROM A HEAVY HYDROCARBON FEED
Abstract
The present invention relates to a process for producing
monoaromatic hydrocarbons from a hydrocarbon feed comprising
polyaromatics, the process comprising contacting said feed in the
presence of hydrogen with a M/zeolite catalyst under hydrocracking
process conditions.
Inventors: |
Aramburo; Luis; (Geleen,
NL) ; van Kimmenade; Emiel; (Geleen, NL) ;
Farmer; Dustin; (Houston, TX) ; Stevenson; Scott
A.; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SABIC Global Technologies B.V. |
Bergen op Zoom |
|
NL |
|
|
Family ID: |
54252091 |
Appl. No.: |
15/762817 |
Filed: |
September 15, 2016 |
PCT Filed: |
September 15, 2016 |
PCT NO: |
PCT/EP2016/071860 |
371 Date: |
March 23, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 2400/30 20130101;
B01J 29/126 20130101; B01J 35/1057 20130101; C10G 47/18
20130101 |
International
Class: |
C10G 47/18 20060101
C10G047/18; B01J 29/12 20060101 B01J029/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2015 |
EP |
15187657.0 |
Claims
1. A process for producing monoaromatic hydrocarbons from a
hydrocarbon feed comprising polyaromatics, the process comprising:
contacting the feed in the presence of hydrogen with a M/zeolite
catalyst at a pressure of ambient-65 bara, a temperature of
350-500.degree. C., a WHSV of 0.1-10 h.sup.-1 and a H.sub.2/HC
ratio of 1-20, wherein said M/zeolite catalyst comprises 0.05-2.5
wt-% of element M, wherein said element M is one or more elements
selected from Group 10 of the Periodic Table of Elements; and an
aluminosilicate zeolite having a pore size of 6-8 .ANG. and a
SiO.sub.2/Al.sub.2O.sub.3 ratio of 50-120.
2. The process according to claim 1, wherein the process conditions
comprise a pressure of 10-40 bara.
3. The process according to claim 2, wherein the process conditions
further comprise a temperature of 400-470.degree. C., a WHSV of 1-3
h.sup.-1 and a H.sub.2/HC ratio of 3-10.
4. The process according to claim 1, wherein the M/zeolite catalyst
comprises an aluminosilicate zeolite having a
SiO.sub.2/Al.sub.2O.sub.3 ratio of 60-100.
5. The process according to claim 1, wherein the M/zeolite catalyst
comprises 0.5-2 wt-% of element M.
6. The process according to claim 1, wherein element M is one or
more elements selected from the group consisting of Pd and Pt.
7. The process according to claim 1, wherein the aluminosilicate
zeolite has a 12-ring structure.
8. The process according to claim 1, wherein the aluminosilicate
zeolite comprises super cages having a size of 12-14 .ANG..
9. The process according to claim 8, wherein the aluminosilicate
zeolite is zeolite Y.
10. The process according to claim 9, wherein the zeolite Y is
partially dealuminated.
11. The process according to claim 1, wherein the hydrocarbon feed
is selected from the group consisting of heavy cycle oil, light
cycle oil, carbon black oil, cracked distillate and pyoil.
Description
[0001] The present invention relates to a process for producing
monoaromatic hydrocarbons from a hydrocarbon feed comprising
polyaromatics, the process comprising contacting said feed in the
presence of hydrogen with a M/zeolite catalyst under hydrocracking
process conditions.
[0002] Processes for producing monoaromatic hydrocarbons described
in Table 4 from heavy hydrocarbon feeds have been previously
described. For instance, US 2007/0062848 describes a process for
hydrocracking a feed comprising not less than 20 weight % of one or
more aromatic compounds containing at least two fused aromatic
rings to produce a product stream comprising C2-4 alkanes and BTX
comprising an aromatic hydrogenation step and a separate ring
cleavage step.
[0003] Ma et al. (2007) Catal Letters 116, 149-154 describe the
coupled hydrogenation and ring opening of tetralin on potassium
modified Pt/zeolite Y catalysts. The process of Ma et al. is
characterized in that the BTX yield is relatively low. Ma et al.
(2007) shows that the extent of successive cracking reactions can
be reduced by introducing potassium into a Pt/zeolite Y catalyst.
As a result thereof, however, the process of Ma et al. (2007) has a
relatively high selectivity for non-aromatic C5-C9
hydrocarbons.
[0004] It was an object of the present invention to provide an
improved process which allows the selective conversion of a heavy
hydrocarbon feedstock comprising polyaromatics to monoaromatic
hydrocarbons and which has a low selectivity towards unwanted
side-products such as methane and/or lower paraffinic hydrocarbons
such as LPG and non-aromatic C5-C9 hydrocarbons.
[0005] The solution to the above problem is achieved by providing
the embodiments as described herein below and as characterized in
the claims. Accordingly, the present invention provides a process
for producing monoaromatic hydrocarbons from a hydrocarbon feed
comprising polyaromatics, the process comprising contacting the
feed in the presence of hydrogen with a M/zeolite catalyst at a
pressure of ambient-65 bara, a temperature of 350-500.degree. C., a
WHSV of 0.1-10 h.sup.-1 and a H.sub.2/HC ratio of 1-20,
[0006] wherein said M/zeolite catalyst comprises:
[0007] 0.05-2.5 wt-% of element M, wherein said element M is one or
more elements selected from Group 10 of the Periodic Table of
Elements; and
[0008] an aluminosilicate zeolite having a pore size of 6-8 .ANG.
and a SiO.sub.2/Al.sub.2O.sub.3 ratio of 50-120.
[0009] In the context of the present invention, it was surprisingly
found that by specifically selecting the M/zeolite catalyst of the
present invention and selecting a pressure of ambient-65 bara, a
temperature of 350-500.degree. C., a WHSV of 0.1-10 h.sup.-1 and a
H.sub.2/HC ratio of 1-20 as process conditions, a heavy hydrocarbon
feed comprising polyaromatic hydrocarbon compounds can be more
efficiently converted to monoaromatic hydrocarbons. Particularly,
the production of unwanted side products such as methane and/or
C5-C9 hydrocarbons can be reduced by selecting the process
conditions as defined herein in combination with the catalyst of
the present invention over a catalyst and process conditions as
described in the prior art, such as Ma et al, which for instance
involves a process temperature of 100-300.degree. C.
[0010] The term "aromatic hydrocarbons" or "aromatics" is very well
known in the art. Accordingly, the term "aromatic hydrocarbon"
relates to cyclically conjugated hydrocarbon with a stability (due
to delocalization) that is significantly greater than that of a
hypothetical localized structure (e.g. Kekule structure). The most
common method for determining aromaticity of a given hydrocarbon is
the observation of diatropicity in the 1H NMR spectrum, for example
the presence of chemical shifts in the range of from 7.2 to 7.3 ppm
for benzene ring protons. As used herein, the term "polyaromatics"
or "polyaromatic hydrocarbons" relates to hydrocarbons having more
than one aromatic ring. As used herein, the term "monoaromatic
hydrocarbons" or "monoaromatics" relates to a mixture of aromatic
hydrocarbons having only one aromatic ring.
[0011] The term "BTX" as used herein relates to a mixture of
benzene, toluene and xylenes. Preferably, the product produced in
the process of the present invention comprises further useful
aromatic hydrocarbons such as ethylbenzene. Accordingly, the
present invention preferably provides a process for producing a
mixture of benzene, toluene xylenes and ethylbenzene ("BTXE"). The
product as produced may be a physical mixture of the different
aromatic hydrocarbons or may be directly subjected to further
separation, e.g. by distillation, to provide different purified
product streams. Such purified product stream may include a benzene
product stream, a toluene product stream, a xylene product stream
and/or an ethylbenzene product stream.
[0012] As used herein, the term "C# hydrocarbons", or "C#", wherein
"#" is a positive integer, is meant to describe all hydrocarbons
having # carbon atoms. Moreover, the term "C#+ hydrocarbons" is
meant to describe all hydrocarbon molecules having # or more carbon
atoms. Accordingly, the term "C9+ hydrocarbons" is meant to
describe a mixture of hydrocarbons having 9 or more carbon atoms.
The term "C9+ alkanes" accordingly relates to alkanes having 9 or
more carbon atoms.
[0013] The term "LPG" as used herein refers to the well-established
acronym for the term "liquefied petroleum gas". LPG generally
consists of a blend of C2-C4 hydrocarbons i.e. a mixture of C2, C3,
and C4 hydrocarbons.
[0014] Accordingly, the process of the present invention involves
contacting a hydrocarbon feed in the presence of hydrogen to a
selective catalyst under specifically selected process
conditions.
[0015] The hydrocarbon feed used in the process of the present
invention comprises polyaromatics. The term "hydrocarbon feed" as
used herein relates to the hydrocarbon mixture that is subjected to
the process of the present invention. Preferably, the hydrocarbon
feed used in the process of the present invention comprises at
least 10 wt-% polyaromatics, more preferably at least 20 wt-%
polyaromatics and most preferably at least 30 wt-% polyaromatics.
Preferably, the hydrocarbon feed used in the process of the present
invention is selected from the group consisting of heavy cycle oil,
light cycle oil, carbon black oil, cracked distillate and
pyoil.
[0016] The specifically selected process conditions used in the
process of the present invention comprise a pressure of ambient-65
bara, a temperature of 350-500.degree. C., a WHSV of 0.1-10
h.sup.-1 and a "hydrogen to hydrocarbon" ratio (H.sub.2/HC ratio)
of 1-20.
[0017] Preferably, the process conditions comprise a pressure of
10-40 bara.
[0018] Preferably, the process conditions further comprise a
temperature of temperature of 400-470.degree. C., a WHSV of 1-3
h.sup.-1 and a H.sub.2/HC ratio of 3-10.
[0019] The selective catalyst used in the process of the present
invention is described herein as M/zeolite catalyst, wherein said
M/zeolite catalyst comprises 0.05-2.5 wt-% of element M, wherein
said element M is one or more elements selected from Group 10 of
the Periodic Table of Elements; and an aluminosilicate zeolite
having a pore size of 6-8 .ANG. and a SiO.sub.2/Al.sub.2O.sub.3
ratio of 50-120.
[0020] Zeolites are well-known molecular sieves having a
well-defined pore size. As used herein, the term "zeolite" or
"aluminosilicate zeolite" relates to an aluminosilicate molecular
sieve. An overview of their characteristics is for example provided
by the chapter on Molecular Sieves in Kirk-Othmer Encyclopedia of
Chemical Technology, Volume 16, p 811-853; in Atlas of Zeolite
Framework Types, 5th edition, (Elsevier, 2001). Preferably, the
catalyst comprises a large pore size aluminosilicate zeolite.
Suitable zeolites include, but are not limited to, zeolite Y,
faujasite (FAU), beta zeolite (BEA) and chabazite (CHA). The term
"large pore zeolite" is commonly used in the field of zeolite
catalysts. Accordingly, a large pore size zeolite is a zeolite
having a pore size of 6-8 .ANG..
[0021] The aluminosilicate zeolite used in the process of the
present invention has a SiO.sub.2/Al.sub.2O.sub.3 ratio of 50-120.
Means and methods for quantifying the SiO.sub.2 to Al.sub.2O.sub.3
molar ratio of a zeolite are well known in the art and include, but
are not limited to AAS (Atomic Absorption Spectrometer) or ICP
(Inductively Coupled Plasma Spectrometry) analysis.
[0022] Preferably, the M/zeolite catalyst comprises an
aluminosilicate zeolite having a SiO.sub.2/Al.sub.2O.sub.3 ratio of
60-100. More preferably, the M/zeolite catalyst comprises an
aluminosilicate zeolite having a SiO.sub.2/Al.sub.2O.sub.3 ratio of
70-90, even more preferably a SiO.sub.2/Al.sub.2O.sub.3 ratio of
75-85 and most preferably a SiO.sub.2/Al.sub.2O.sub.3 ratio of
about 80.
[0023] Accordingly, element "M" as used herein is one or more
elements selected from Group 10 of the Periodic Table of Elements.
Preferably, the M/zeolite catalyst comprises 0.5-2 wt-% of element
M. All weight percentages of element M as provided herein relate to
the amount of element M in relation to the total catalyst
composition. Preferably, element M is one or more elements selected
from the group consisting of Pd and Pt. Most preferably, element M
is Pt.
[0024] The catalyst composition as used in the process of the
present invention may comprise further components such as a binder.
Known binders include, but are not limited to silica, alumina and
clay, such as kaolin. Alumina (Al.sub.2O.sub.3) is a preferred
binder. The catalyst composition of the present invention
preferably comprises at least 10 wt-%, most preferably at least 20
wt-% binder and preferably comprises up to 40 wt-% binder.
[0025] The catalyst composition is preferably formed into shaped
catalyst particles by any known technique, for instance by
extrusion.
[0026] Preferably, the aluminosilicate zeolite has a 12-ring
structure. These specific aluminosilicate zeolites are well known
to the skilled man. An overview of their characteristics is for
example provided by the Atlas of Zeolite Framework Types, 5th
edition, (Elsevier, 2001). Accordingly, an aluminosilicate zeolite
having a 12-ring structure is an aluminosilicate zeolite wherein
the pore is formed by a ring consisting of 12 [SiO.sub.4] or
[AlO.sub.4].sup.+ tetrahedra.
[0027] Preferably, the aluminosilicate zeolite is zeolite Y.
Depending on the silica-to-alumina molar ratio
("SiO.sub.2/Al.sub.2O.sub.3 molar ratio" or
"SiO.sub.2/Al.sub.2O.sub.3 ratio") of their framework, synthetic
faujasite zeolites are divided into zeolite X and zeolite Y. In X
zeolites the SiO.sub.2/Al.sub.2O.sub.3 ratio is between 2 and 3,
while in Y zeolites it is 3 or higher. Accordingly, zeolite Y is a
synthetic faujasite zeolite having a SiO.sub.2/Al.sub.2O.sub.3
ratio in their framework of 3 or more. Preferably, the zeolite in
the selective alkylation catalyst is in the so-called hydrogen
form, meaning that its sodium or potassium content is very low,
preferably below 0.1, 0.05, 0.02 or 0.01 wt-%; more preferably
presence of sodium is below detection limits.
[0028] Preferably, the zeolite y is partially dealuminated.
Preferably, the zeolite Y used in the process of the present
invention has a SiO.sub.2/Al.sub.2O.sub.3 ratio of 60-100. More
preferably, the zeolite Y used in the process of the present
invention has a SiO.sub.2/Al.sub.2O.sub.3 ratio of 70-90.
Preferably, the partially dealuminated zeolite is prepared by
controlling SiO.sub.2/Al.sub.2O.sub.3 ratio during zeolite
synthesis. Alternatively, the zeolite may be partially dealuminated
by a post-synthesis modification. Means and methods to obtain
dealuminated zeolite by post-synthesis modification are well known
in the art and include, but are not limited to the acid leaching
technique; see e.g. Post-synthesis Modification I; Molecular
Sieves, Volume 3; Eds. H. G. Karge, J. Weitkamp; Year (2002); Pages
204-255. The aluminosilicate zeolite may comprise super cages
having a size of 12-14 .ANG.. Means and methods for preparing
zeolites comprising super cages are well-known in the art and
comprise zeolite post-treatments such as acid leaching and
steaming, among others. (Angew. Chem., Int. Ed. 2010, 49, 10074,
ACS nano, 4 (2013) 3698).
[0029] The process of the present invention produces monoaromatic
hydrocarbons as a process product. Preferably, the process of the
present invention produces at least 20 wt-% monoaromatic
hydrocarbons of the total hydrocarbon process product, more
preferably at least 25 wt-% monoaromatic hydrocarbons of the total
hydrocarbon process product, and most preferably at least 30 wt-%
monoaromatic hydrocarbons of the total hydrocarbon process product.
Preferably, the process of the present invention produces less than
1.5 wt-% methane of the total hydrocarbon process product, more
preferably less than 1 wt-% methane of the total hydrocarbon
process product and most preferably less than 0.5 wt-% methane of
the total hydrocarbon process product.
[0030] It is noted that the invention relates to all possible
combinations of features described herein, particularly features
recited in the claims.
[0031] It is further noted that the term "comprising" does not
exclude the presence of other elements. However, it is also to be
understood that a description on a product comprising certain
components also discloses a product consisting of these components.
Similarly, it is also to be understood that a description on a
process comprising certain steps also discloses a process
consisting of these steps.
EXAMPLE
[0032] Catalyst Preparation
[0033] Physical Mixture Catalyst:
[0034] The physical mixtures of hydrogenation and solid acid
catalysts are composed of commercially available catalyst samples.
The hydrogenation catalyst is a Pt/Al.sub.2O.sub.3 from UOP, namely
R-12. The zeolite is an unmodified zeolite Y from Zeolyst, namely
CBV 780. These samples have been mixed in a 1 to 1 weight
ratio.
[0035] Bifunctional Pt/Zeolite Y Catalyst:
[0036] 65 grams of Zeolyst CBV 780 are divided into 3 ceramic
dishes and calcined in air at 100.degree. C. for 3 hours to
300.degree. C. and then to 550.degree. C. for 10 hours using a ramp
rate of 3.degree. C./min.
[0037] After calcination, 15 grams of pre-dried sample are
dispersed in 1 liter of deionized water and stirred at 65.degree.
C. overnight. The next day the temperature is raised to 70.degree.
C. and a solution of 0.317 g of Pt(NH.sub.3).sub.4 (NO.sub.4).sub.2
is dissolved in 76.4 g of DI-H20 and added drop wise over a period
of 7 hours. The material is allowed to stir overnight at 70.degree.
C. prior to filtering off the liquid. The filter cake is
re-suspended in 1 liter of fresh DI-H20 and allowed to stir for 15
min and subsequently filtered again. The washing step is repeated
twice more. The material is then allowed to dry overnight on filter
paper at room temperature. Next, the material is dried at
80.degree. C. for 3 hours, pressed (10,000 psi), crushed and sieved
(35-60 mesh sizing scheme). The sized material is loaded in a tube
furnace with an air flow rate of 2.2 L/min. The furnace is heated
to 100.degree. C. for 3 hours then to 300.degree. C. for 3 hours at
a ramp rate of 0.2.degree. C./min. Subsequently, the material is
further calcined to 350.degree. C. at 0.2.degree. C./min for 3
hours. The flows rates are then turned down to down to 1 L/min for
1 hour then to 345 ml/min for 1 hour while 350.degree. C. is
maintained. The material is then transferred to the calcination
oven and calcined for 3 hours in air using the same ramp rate of
0.2.degree. C./min.
[0038] Experimental Set-Up
[0039] The experimental program was conducted on a fully automated
16-fold trickle-flow hydro process unit allowing uninterrupted
catalyst testing. The operating range of this unit is summarized in
Table.
[0040] The 16-fold trickle-flow hydro processing unit operates as
follows: The feed is preheated and mixed with hydrogen prior to
entering the evaporation zone located on the top part of the
set-up. Therein the mixture is heated to the selected reaction
conditions. The pressure in the reaction section is maintained with
a nitrogen pressure hold gas system (PHG) at the reactor outlet.
The reactor section is composed of a 5 mm internal diameter tube
with an isothermal zone of 50 mm at the highest operating
temperature. Once the reaction has taken place the effluent is sent
to a condenser kept at 75.degree. C. Therein the gas is separated
from the liquid and sent to an online GC (every 90 min). The liquid
collected during reaction is stored and subsequently analyzed
offline in a GC-MS. Both, the gas and liquid flows are precisely
measured to obtain the combined effluent composition.
TABLE-US-00001 TABLE 1 16-fold trickle-flow hydro processing unit
specifications. Set-up specifications Temperature up to 500.degree.
C. Pressure up to 100 bara Operation mode Trickle-bed Catalysts
volume up to 1.92 ml Reactor inner diameter 5 mm Gases H.sub.2,
N.sub.2, Ar
[0041] Model Feed Composition
[0042] The experiments have been carried out with a synthetic feed
composed of paraffin's (25 wt %), mono-aromatics (20 wt %),
di-aromatics (55 wt %) and tri-aromatics (5 wt %). This is
summarized in table 2.
TABLE-US-00002 TABLE 2 Model feed composition details. Model Feed
Decane 25 wt % Propylbenzene 20 wt % Naphthalene 25 wt %
1-Methylnaphthalene 10 wt % 2-Methylnaphthalene 15 wt % Anthracene
2 wt % Phenantrene 3 wt %
[0043] Catalyst Preparation and Reactor Loading:
[0044] The series of catalysts tested displayed different sizes and
shapes. To minimize the influence of external mass transfer
limitations and compare the intrinsic reactivity of each catalyst,
similar sieved fractions were used. To this end, zeolite powders
were bound with alumina sol, dried, calcined and sieved to the
desired size. The zeolite containing samples (namely, solid acid
catalysts and/or bifunctional catalysts) were mixed in a 7 to 3
ratio with Dispersal.RTM. and the resulting mixture mixed with
water (1 to 5 ratio). Subsequently, the slurry was milled (5 min,
600 rpm), dried in a hot box (110.degree. C., overnight), calcined
in air (300.degree. C., 6 h) and sieved to a target fraction of
125-160 .mu.m. On the other hand, the hydrogenation catalysts were
milled and sieved to the same target fraction as the zeolite
containing samples.
[0045] The catalysts were loaded in the reactors together with
silicon carbide diluent to form a bed which is ring shaped around a
thermowell. A thorough calibration was performed to determine the
isothermal zone of the 16 parallel reactor set-up under the
temperature conditions tested.
[0046] Activation Protocol
[0047] The activation and soaking protocol details are summarized
in Table 3. After loading the catalyst in the reactor the
activation procedure is performed to reduce the metal particles
contained in the catalyst. Subsequently, the hydrogen feed is
replaced by a mixture of hydrogen and the hydrocarbon feed used in
the experiments while the sample is heated up slowly to reaction
conditions. This is the so-called soaking procedure.
TABLE-US-00003 TABLE 3 Activation and soaking protocol details.
Activation procedure Soaking procedure Temperature 60-400.degree.
C. Temperature 60.degree. C. Heating ramp 1.degree. C./min, WHSV 2
h.sup.-1 2 h hold at 400.degree. C. Purge step N.sub.2 during 10
min Purge step N2 during 10 min Reduction H.sub.2 H.sub.2 flow 10
(I/h) step H2 flow 41.5 (I/h) Pressure 30 bara Pressure 30 bara
Duration 16 h Duration 460 min + Cool down
[0048] Experimental Results
[0049] The physical mixture catalyst and bifunctional Pt/Zeolite Y
catalyst, all prepared as described herein above, were contacted
with the model feed using the following reaction conditions: a WHSV
of 1 h.sup.-1, a H.sub.2:HC ratio of 10, a pressure of 30 bara and
a temperature of 400 or 450.degree. C. The process was performed in
a continuous system that operated in steady state conditions. In
Table 4 the experimental results are describes as an average result
of a measuring period of 24 h. Data were generated using GC-MS as
described herein above.
TABLE-US-00004 TABLE 4 Experimental results Mono- Temperature
aromatics catalyst (.degree. C.) (wt %) Pt/Zeolite Y 400 26.8
Physical 400 21.7 mixture Pt/Zeolite Y 450 33.6 Physical 450 28
mixture
* * * * *